Best Quality Nitrile (NBR) & Hydrogenated Nitrile (HNBR), Viton (FPM), Silicone (MVQ) & Fluorosilicone (MFQ), Ethylene Propylene Diene Rubber (EPDM) & Peroxide cured. Others include Polytetrafluoroethylene (PTFE) as well as PTFE Encapsulated (FEP) & (PFA), Neoprene (CR), Aflas, PEEK,  Polyurethane (PU), Perfluoroelastomers (FFKM, FFPM, Kalrez, Chemraz, Simrez and Perlast, MBSG75B, MBS-G75B).